I think nethunter should try to work newer model of phones.
The moto g5 is a nice cellphone.
Not as fast as a Nexus 6 (being 3 gb ram)
The moto g5 packes a decent size at 2 gb
Or some models 3gb ram available.
With an intigraded fingerprint scanner.
Nexus 6 released in 2014 is getting a little outdated by newer models.
Moto g5 releasd in 2017.